The invention relates generally to reactors for producing gas from powdery fuels and more particularly it relates to a device for relieving pressure from such a reactor. The reactor is of the type in which a powdery fuel is gasified under pressure whereby hydrogen and carbon-monoxide containing gases are produced which directly or after an initial processing are employed as heating gas, synthetic gas, reduction gas, mixing complements for other gases such as for example coal gas and the like. As a powdery fuel in this type of reactor is usually used finely divided brown coal and/or stone coal as well as finely crushed carbon containing solid residuals of a coal refining process as well as of a crude oil refining process or solid carbon containing organic material of other origin (such as, for example, lumber waste, used tires, plastic wastes and the like) also finely divided in the form of dust.
In view of the wide variety of applicable powdery fuels, a particularly advantageous method of gasification of such finely divided fuel materials has proved to be a flame reaction between the powdery fuel and oxygen containing oxidation agent. In carrying out such a known technology at which the gas is produced at an increased pressure, there result however problems how to discharge hot-pressurized gases from the reactor when the latter discontinues its operation or in the case of emergency. The produced hot gases are namely under pressure between 20 to 50 bars, and to handle such pressures requires additional technical measures. It has been devised to conduct the hot high-pressure gases through the discharge opening from the reactor which is normally arranged at the bottom of the latter and serves for discharging both the crude gas and the liquid slag, and in the range of discharge opening to cool the gases by a spray of water, or by introducing the gases in a gas purifying apparatus. The suggested solution, however, has several disadvantages. As the first disadvantage occurs in the case of feeding failure of the powdery fuel through the burner inasmuch before the feeding of the oxygen is shut off a certain amount of the oxygen reaches the reaction chamber and during the discharge of gases through a common discharge port the oxygen containing gas enters the subsequent processing units of the gas producing plant and may endanger the latter. The second disadvantage of this prior art solution occurs when the common discharge port for the crude gas and the slag becomes blocked by slag deposits and by refractory material coming loose from the lining of reactor so that the pressure relief of the gas in the devised passage is no longer possible.
A device is also known in which a connecting piece is arranged in the burner instert opening into the reaction chamber or in the upper part of the reactor whereby an interlocking mechanism with a subsequently connected quenching circuit is attached to this connecting piece. The disadvantage of this device resides in the necessity of maintaining continuous rinsing of the interlocking mechanism by an inert gas in order to insure a proper function of this mechanism during the operation of the reactor. As a result the operational cost increases due the applied auxiliary cooling medium such as nitrogen, for example, and the quality of the produced gases especially as regards their heating value decreases. Another disadvantage of this solution results from the fact that at certain operational conditions in the reactor the discharge opening becomes clogged due to the incrustation of slag and due to the slag deposition and the operability and the proper functioning of the reactor is impaired. A third disadvantage results also from the fact that the additional interlocking mechanism including the connecting piece has to be additionally cooled by means of a cooling liquid in order to insure the operability of the reactor at high temperatures. Accordingly an increased consumption of cooling water and of energy for supplying the latter to the reactor will result.